Abstract: The electronic pages of this journal have, for the past few years, contained numerous examples of virtual reality maps: from planning for extra residential units in downtown Ann Arbor to tracking rugged voyages of Lewis and Clark. Many maps cover large areas of terrain; they are global in scale. Virtual reality, however, often is best executed in the small, at a local scale (Beier (lectures in Engineering 477, The University of Michigan), Crispen). The virtual maps tend to become large in file size quickly, causing the maps not to load properly. One problem is that software that easily creates virtual maps may not also optimize file size. That persistent problem of the virtual modeler can be partially addressed by importing Virtual Reality Modeling Language (vrml) files exported from Geographic Information System software (GIS software) into a software package that executes polygon reduction of the vrml code. Beyond such reduction, however, there remains the geographer's dilemma of scale transformation and a need to map both globally and locally. A classical way to execute such transformation is to arrange the spatial information in layers of a nested hierarchy and use a well-defined transformation to move from one level of that hierarchy to another. In the case of virtual reality maps (VR-maps), one puts individual maps in separate layers, separating maps before they become too heavy to run smoothly, or adequately, on current computing equipment (the creator, of course, needs to decide the target audience and the computing environment in which its members are likely to function).
Earlier work on creating a 3D Atlas of Ann Arbor has produced thousands of separate virtual maps of the downtown (inventory of previous work; click on the "Archive" button). Some are maps that show the current stock of buildings. Others are maps that suggest future buildout scenarios based on concepts provided by leading architectural and construction experts. The images below show screen capture of separate virtual reality models. The image on this offers a simple solution to link the different hyperlinked images, using kiosks that transform the user, via the internet, from one hierarchical level to another.